Apparatus for decomposing alkali sulfates.



No.646,3l3. Patented Mar. 27, I900. J. G. A. RHODIN.

APPARATUS FOB DEGOIIPOSING ALKALI SULFA TES.

(Application filed Mar. 16; 1899.)

(No Model.)

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JOHN GUSTAF ADOLF RHODIN, OF SALE, ENGLAND APPARATUS FOR DVECOMPOSINGALKALI SULFATE.'

SPECIFICATION forming part of Letters Iate nt N 0. 646,313, dated March27, 1906. Application filed March 18,1899. Sria1No.'709,6'73. (Nomodel.)

To all whom it-may concern.-

Be it known that I,'JoHN GUSTAF ADOLF RHoDIN, a citizen of the Kingdomof Sweden, residing at Glamis House, Montague road, in the village ofSale, in the county of Chester, England, have invented a certain new anduseful Apparatus for Decomposing Alkali Sulfates for Production ofCaustic Alkali and Copper Sulfate, (for which I have made ap plicationfor a patent in Great Britain, dated August 18, 1898, No.17,794t,) ofwhich the following is a specification. I

This invention relates to the construction of electrolytic apparatusconsisting of a cell divided by a porous partition into twocompartments. The anode-compartment is charged with sodium sulfate, inwhich there is an anode of copper connected to the posi-- tive terminalof a source of electricity. The oathode=compartment is charged with anaqueous solution of caustic soda and has in it a metal cathode connectedto the negative terminal of the source of electricity. When the cell isput in circuit, the sodium sulfate is decomposed, its sulfuric acidcombining with a portion of the copper anode to form copper sulfate,while its sodium passes through the porous partition to thecathode-compartment, where it becomes oxidized, so as to form causticsoda by oxygen from the water of the solution in thecathode-compartment, hydrogen being liberated and escaping. Thus thecopper-sulfate solution in the anode-compartment and the caustic-sodasolution in the cathode-compartment become stronger and stronger and mayfrom time to time be wholly or partly removed, or sodium sulfate may becontinuously fed into the anode compartment, copper-sulfate solutionbeing drawn off therefrom and caustic-sodasolution being drawn from thecathode-compartment.

The cathode is mercury, which forms an amalgam with the sodium liberatedin the anode-compartment, this amalgam being decomposed in the presenceof water regenerating the mercury and producing caustic soda byoxidation of the sodium.

The apparatus according to my invention for operating in the manner setforth is represented by the accompanying drawings.

Figure 1 is a section, and Fig. 2 is in one half a top plan, and theother half is a sec tional plan on the line A of Fig. l. I

Within a basin-like vessel a, of insulating material, the bottom ofwhich has ribs b inclined to radii and projecting a little upward, asmaller basin-like vessel 0, also of insulating material, fixed on avertical shaft d, is caused to revolve by any convenient means, such asa belt acting on a pulley on the shaft 01. The lower part of the vessel0 consists of ribs, with openings between them, carrying a porousdiaphragm e, which slopes down toward a central well. The shaft 01revolvesin a bearing g and has on it an insulated ring h, on which bearsa brush connected by a conductor to the positive terminal of a source ofelectricity. From the ring h are suspended several copper gratings j,which constitute the anode. A layerof mercury 7c covers the lower partof the vessel CL, and a conductor Z nal of the source of electricity. Onthe vessel 0 being charged with solution of sodium sulfate and'theapparatus put in circuit and the shaft d being caused to revolve thecopper anodes j are gradually dissolved by the sulfuric acid resultingfrom decomposition of the sodium sulfate producing copper sulfate, whilethe sodium forms an amalgam with the mercury. The amalgam is caused bythe downwardly-projecting ribs m forming compartments on the under sideof the basin 0 as it revolves in the direction of the arrow to travelalong the spaces between the ribs 1) toward the periphery of the vessela, and during its travel the sodium becomes oxidized, forming causticsoda, which mixes with the solution in the annular space around 0, whilethe mercury, being heavier when freed from the sodium, flows back towardthe center to take up fresh sodium. When the contents of c consistmostly connects the mercury to the negative termiof copper sulfate,while those of the annular withdrawing the vessel 0. The cocks on thepipesp q may be so adjusted as to keep the flow of copper sulfate andcaustic soda continuous, sodium sulfate being continuously fed into 0.

Although sodium sulfate has been mentioned as the alkali sulfatetreated, the bisulfate might also be dealt with in the same way, alsopotassium sulfate or bisulfate, and instead of copper being employed asthe anode other metals which can be similarly dissolved in the sulfuricacid. liberated from the alkali sulfate can be treated in the same way.

Having thus described the nature of this invention and the best means Iknow of carrying the same into practical effect, I claim- 1. Inapparatus for decomposing alkali sulfates for production of causticalkali and coppersulfate, the combination of avessel, a vesselconcentric within the same and provided with a porous diaphragm, meansfor revolving the inner vessel, a terminal extending within the outervessel, and a terminal connected with copper anodes in the inner v'esselabove the porous diaphragm, as set forth.

2. In an apparatus of the character described, an inner and an outervessel, a porous diaphragm within theinnervessel,means for revolving theinner vessel, copper anodes suspended Within the inner vessel and a ter-0 minal extending down to a mercury cathode in the outer vessel, as andfor the purpose specified.

3. The combination with the outer vessel containing a mercury cathodeand having ribs upon the upper surface of its bottom, of the innervessel having depending ribs about its center and sloping perforateddiaphragms above the same, means for revolving the inner vessel,andcopper anodes suspended within the inner vessel and connected with theterminal of a source of electricity, as set forth.

4. An outer vessel with ribs, an inner vessel with depending ribs andinclined perforated diaphragm, means for revolving the inner vessel,suspended copper anodes Within the inner vessel, connected with oneterminal of a source of electricity and the other terminal extendingdown to a mercury cathode in the outer vessel, as and for the purposespecified.

In testimony whereof I have hereunto set my hand in presence of twosubscribing witnesses.

JOHN GUSTAF ADOLF RllOlllN.

\Vitnesscsi GEO. J. B. FRANKLIN, W M. HARRIS.

